pub fn parse_vocabulary(value: &Value) -> Option<VocabularyDoc>Expand description
Parse a vocabulary document from its top-level value: a vocabulary: { field, values } marker plus a terms: mapping, each entry either a bare
key (a live term with no metadata) or a { label?, description?, retired? } mapping. Returns None when value carries no vocabulary marker —
i.e. it is not a vocabulary document.
This is the shared file-format half of a controlled vocabulary: Term
and validate_enum already say how to check a value; this says how to
load the term set a document declares, so two independent embedders (a
frontmatter engine, a batch renderer) can point at the same vocabulary
document without either depending on the other.
Key lookup is Value::get, so a duplicated key resolves last-wins, the
same way fig itself reads one. A duplicated term is not a lookup and
yields two Terms with the same value, in declaration order.